BACKGROUND: Models of attention deficit hyperactivity disorder(ADHD) that have proposed a hypodopaminergic state resulting in hypofunction of the prefrontal circuitry have assumed a unitary dopamine system, which largely ignores the distinct functional differences between mesocortical dopamine system and nigrostriatal dopamine system. PURPOSE: The author's goal was to develop a pathophysiological model for ADHD with greater explanotory power than dopaminergic hypofunction hypothesis in prefronal circuitry. MATERIALS AND METHODS: Published clinical findings on ADHD were integrated with data from genetic, pharmacological, neuroimaging studies in human and animals. RESULTS: Molecular genetic studies suggest that three genes may increase the susceptibility to ADHD. The three candidate genes associated with ADHD are each involved in dopaminergic function, and this consistent with the neurobiologic studies implicating catecholamines in the etiology of ADHD. Pharmacological data also provide compelling support for dopamine and noradrenergic hypothesis of ADHD. Neuroimaging studies lend substantial support for the hypothesis that right-sided abnormalities of prefrontal-basal ganglia circuit would be found in ADHD. CONCLUSIONS: The present hypothesis takes advantage of the major differences between the two pertinent dopamine systems. Mesocortical dopamine system, which largely lacks inhibitory autoreceptors, is ideally positioned to regulate cortical inputs, thus improving the signal-to-noise ratio for biologically valued signals. In this circuit, therapeutic doses of stimulants are hypothesized to increase postsynaptic dopamine effects and enhance executive functions. By contrast, symptoms of hyperactivity/impulsivity in ADHD are hypothesized to be associated with relative overactivity of nigrostriatal circuit. This nigrostriatal circuit is tightly regulated by inhibitory autoreceptoors as well as by long distance feedback from the cortex, and slow diffusion of therapeutic doses of stimulant via oral administration is hypothesized to produce a net inhibition of dopaminergic neurotransmission and improves hyperactivity.
Administration, Oral ; Animals ; Attention Deficit Disorder with Hyperactivity* ; Autoreceptors ; Catecholamines ; Diffusion ; Dopamine ; Dopamine Agents ; Executive Function ; Ganglia ; Humans ; Molecular Biology ; Neuroimaging ; Signal-To-Noise Ratio ; Synaptic Transmission

The ability of photochemotherapy(PUVA) or UVA phototherapy to stimulate melangenesis is well known. It is now recognized that the PUVA lentigines, irregular in outline and often more darkly and unevenly pigmented than solar lentigines, are related to the additional pigmentary effects of the PUVA therapy. We present herein four cases of unusual pigmentation after one month of UVB irradiation. Raticulated dark brown pigmentation appeared on the lower extremities of the patients. Histopathologicially, an increase in melanin in the basal layer was found, but no dysplasia or malignant change. We suggest UVB as the cause of this unusual hyperpigmentation.
Humans ; Hyperpigmentation ; Lentigo ; Lower Extremity ; Melanins ; Phototherapy* ; Pigmentation* ; Psoriasis* ; PUVA Therapy

No abstract available.
DNA* ; Genome* ; Nucleopolyhedrovirus* ; Promoter Regions, Genetic*

We designed this study to analyze the causes of repeat surgery in the low back disorder after primary procedure, to evaluate the risk factors and to suggest the rational approachs can prevent and solve the problems related with repeat surgery. We retrospectively reviewed the medical record and radiographs of 24 patients who had sustained persistent or recurrent pain, failed to extended conservative therapy, showing abnormal myelogram and/or CT scan with nerve root compression, and with segmental instability consistent with patients symptom and sign after the primary procedures. We evaluated the functional outcome according to Kims(1986) criteria. The causes of remained or recurrent pain with neurologic symptom were persistent or aggravated lumbar spinal stenosis in 10 cases(42%), recurrent disc herniation in 4 cases(17%), infection in 3 cases(12%), instability in 2 cases(8%) and others in 5 cases(20%). Satisfactory outcome was recorded in 79%(19/24) of patients. The characteristics of the patients associated with satisfactory outcome were those who operated by recurrent disc herniation, instability, retained disc, metal malposition, and nerve root compression by bone chip. But the characteristics of the patients associated with unsatisfactory outcome were those who operated by infection, lumbar spinal stenosis aggravated by degenerative spondylosis and multiple herniated disc, inadequate decompression of lateral and/or foraminal stenosis in aged patients. The most common lesion site was on L4-5 disc, and unsatisfactory result was expected at the upper lumbar spine involvement. Favorable outcome could be expected in the presence of a pain-free interval more than 1 year from the date of the previous operation or persistent symptoms immediately after the initial operaion. We were expected the risk factors leading to repeat surgery were old aged(more than 60) patients, upper lumbar spine involvement and multiple lumbar disc herniation. Postoperative diskitis or osteomyelitis, pain free interval more than 1 month or less than 1 year, and those who had a revision on the lumbar spine previously could be considered as a poor prognostic indicators. When surgery is indicated for degenerative lumbar spinal disorders, adequate diagnostic tests and the execution of appropriate procedures based upon this information should be carried out to prevent the repeat surgery in the low back disorders. Adequate postoperative management can reduce the occurrence of failed back surgery syndrome and in cases necessitating repeat surgery, thorough analysis of causes following proper surgical stabilization can reduce the operative morbidity with early return to daily life.
Constriction, Pathologic ; Decompression ; Diagnostic Tests, Routine ; Discitis ; Failed Back Surgery Syndrome ; Humans ; Intervertebral Disc Displacement ; Medical Records ; Neurologic Manifestations ; Osteomyelitis ; Radiculopathy ; Reoperation* ; Retrospective Studies ; Risk Factors ; Spinal Stenosis ; Spine ; Spondylosis ; Tomography, X-Ray Computed

A 31-year-old male patient had malignant atrophic papulosis that afected the skin only. He had multiple typical porcelain-white skin lesion on the face and trunk without abdominal symptoms. Histopathologic studies showed moderate inflammatory infiltration in addition to the typical cone-shaped region of necrobiosis, There are no satisfactory treatment modes, and in the present case, the patient's condition improved transiently on oral medication of aspirin, but we lost the contact with him afterwards.
Adult ; Aspirin ; Humans ; Male ; Malignant Atrophic Papulosis* ; Necrobiotic Disorders ; Skin

The dysplastic hip presents problems to the orthopedic surgeon in the reconstruction of hip using total hip prosthesis. The use of bone grafts to reconstruct the lateral acetabular bone deficiency is very popular. We investigated in 23 patients(5 cemented cup and 18 cementless cup). Sixteen patients were women and seven were men, whose average age was 42.4 years old; their average followup was 4.6 years. The average Harris hip score improved from a preoperative value of 48 points to a postoperative value of 87 points. Five cases showed radiographic loosening, in which 3 cases loosening from five cemented cup and 2 cases from cementless cup arthroplasty. Radiolucent lines were observed more frequently with cemented cups at last follow-up. Of the 23 cases, 18(78%) was successful. Postoperatively limping was a major problem because most patients in this series had unilateal disease. The grafted bone was incoporated by an average time of 7.4 months, and minor resorption was showed at last follow-up. In our series, cementless cups with autogenous bone graft noted good results than cemented cup arthroplasty.
Acetabulum ; Arthroplasty ; Arthroplasty, Replacement, Hip* ; Female ; Follow-Up Studies ; Hip Prosthesis ; Hip* ; Humans ; Male ; Orthopedics ; Transplants

No abstract available.
Humans ; Lower Urinary Tract Symptoms* ; Prostate* ; Urethral Obstruction*

We observed a 51-year-old male, who developed depigmented patches on the lower abdomen after photochemotherapy(PUVA) of psoriasis without evidence of phototoxic reaction. The depigmented patches did not orginate from the sites of previous psoriatic lesions. Fontana-Masson stain of the biopsy specimen revealed nearly absent melanin pigments in the epidrmis of the hypopigmented patch, while lots of pigments were obsereved on the surrounding hyperpigmented area. Electron micrograph showed no melanocytes in the hypopigmented patch. Thus we report this case as having vitiliginous patches induced by photochemotherapy of psoriasis.
Abdomen ; Biopsy ; Humans ; Male ; Melanins ; Melanocytes ; Middle Aged ; Photochemotherapy* ; Psoriasis* ; Vitiligo

A case of complete loss of penile skin treated with scrotal skin graft was presented in a 26 year old male. This case was noted to be a complete loss of penile skin which was developed under local anesthesia with formalin 30 cc during circumcision. The implantation of the penis in the scrotum was performed by the scrotal tunnel method. Complete logs of penile skin was restored by implanting the denuded surface under the subcutaneous tissue of the scrotum.
Adult ; Anesthesia, Local ; Circumcision, Male ; Female ; Formaldehyde ; Humans ; Male ; Penis ; Scrotum ; Skin* ; Subcutaneous Tissue ; Transplants*

To investigate MR artifacts induced by metallic implants, scans were obtained using both the ferromagnetic Drake lip and the non ferromagnetic Yasargil clip. Scan were taken through the area of clips using geometrical phantom. The MRI was performed by spin echo technique and gradient echo technique on both 2.0T and 0.5T MR unit. The luthors evaluated the nature and differences of artifacts in each sequence and parameter. Artifacts induced by both lips were noted in the direction of frequency encoding gradient, and consisted of region of signal loss abutted in one side by survilinear region of bright signal. Geometric distortion of image was marked in the Drake clip, out was minimal in the Yasargil clip under both 2.0T and 0.5T. Artifacts were more pronounced in the gradient echo technique than those of the spin echo technique on both 2.0T and 0.5T. Although there were no differences n the nature of artifacts induced by the Drake clip among each parameter in the spin echo technique under 2.0T, artifacts were slightly more pronounced on T2 weighted image under the 0.5T field, but no differences were found in the nature of artifacts induced by the Yasargil clip in the spin echo technique under, both the 2.0T and 0.5T fields. Marked artifacts were induced through the small area of the Drake clip which were included in the scan plane, but induced artifacts were small when a small area of the Yasargil clip was included in the scan plane. It seemed likely hat artifacts were slightly more pronounced in the 2.0T than the 0.5T field in both clips, but objective evaluation of the difference was difficult, In conclusion, these results can be an essential basis for the interpretation of MR images or patents with metallic inplants.
Aneurysm* ; Artifacts* ; Lip ; Magnetic Resonance Imaging* ; Magnets